Arthur. — On the Brown Trout introduced into Otago. 475 



immediate ancestors in England ; and as Mr. Francis, in above treatise, 

 tells us that Thames trout spawn early, or in November, and are corres- 

 pondingly early in getting into edible condition in the following spring, I 

 presume I am correct in taking 63 days as the average duration for the 

 hatching of these, and November as their spawning month. If this is so, 

 then this same trout species in Otago takes 78 days to hatch out, and 

 spawns from the middle of June to the end of September, according to 

 locality — the coast streams from June 1st to end of August, and the Waka- 

 tipu streams in September. In other words, the same species of trout here 

 is about two months later in spawning, and the ova ten days to a fortnight 

 longer in hatching than in England. 



Growth in the Shag River, Leith, Lee, Deep Stream, and Upper Taieri, 



1875 to 1883. 

 The weight, as a measure of the growth of our trout, must next receive 

 some attention, and the first question one naturally wants answered is, 

 Have the trout maintained their previous rate of growth during the last five 

 years ? Well, in my first paper, bringing down observations to 1878, five 

 rivers are mentioned, with their heaviest recorded trout as : — Shag Eiver, 

 female trout 16-|lbs., yearly growth 2f lbs. ; Water of Leith, male 12|lbs., 

 yearly growth l|lbs. ; Lee Stream, 5lbs., yearly growth lib. ; Deep Stream, 

 81bs., yearly growth l^lbs. ; and Upper Taieri, female 61bs. 6oz., yearly 

 growth lib. Now it is extremely difficult to compare with the foregoing 

 the growth of trout in the same waters during the past five years. This 

 arises from the principle that it would be hardly correct to assume that the 

 heaviest fish weighed since 1878, were part of the original stock put into 

 those rivers in 1869, unless their extraordinary size should render that sup- 

 position probable. The only other possible solution is one which has not 

 been tried, at least not on a scale sufficient to give any results, and that is 

 such proof as may be got by marking a great number of fish, returning 

 these to the water after being weighed, and re-weighing the same fish years 

 after when again caught. This is the best and most unquestionable test, 

 but until it is made we are constrained to appeal to such approximations as 

 may be got from the average weight of fish per day taken by anglers for 

 each year. From one angler's diary I can give this ; only, however, as re- 

 gards the Lee and Deep Streams. Before doing so I may as well mention 

 the weight of the heaviest single fish killed in each of above rivers from 

 1878 to March 1883 ; also the mean weight of a number of the heaviest, 

 from actual notes of the fish weighed, and in one or two cases from 

 memory. They are these : — Heaviest trout, Shag Eiver, 14lbs., in 1879 ; 

 Leith, 17lbs., in 1880; Lee, lOlbs., in 1882; Deep Stream, lOlbs. (seen 

 but not caught), in 1882; and Upper Taieri Biver, 201bs., in 1880, 



